Hemlocks may be doomed

An exotic insect pest, the hemlock woolly adelgid, continues to destroy hemlock stands throughout the eastern United States.

This past autumn, foresters discovered a large area of infested hemlocks on the lower end of Wykoff Run in Cameron County. Sadly, the infected area was too large to treat.

The insect pest has also been discovered in the nearby Grove Run drainage.

Woolly adelgid feeds on hemlock trees and some spruce species. The egg sacs look like small pieces of cotton. Although some trees die within a few years, most trees live on in a weakened state for many years before finally succumbing.

Hemlocks that are being preyed upon often have an unhealthy thin, grayishgreen appearance, compared to their normal green luster. At certain times they also wear the telltale cottony secretions on their branches and needles.

After hatching in May, adelgid larvae begin searching for feeding sites. Wind, birds and mammals often spread the adelgid to nearby hemlocks. However, in the case of the Wykoff Run infestation, it appears that humans unknowingly transported the larvae.

This outbreak developed near a large group of seasonal camps, suggesting that the insect larvae may have been introduced through importing infected firewood or hitching a ride on an automobile.

This exotic insect is poised to destroy our hemlock forests in northcentral Pennsylvania as it has done through much of the Appalachians, where it has already transformed numerous beautiful hemlock stands into gray skeletons. Without any natural predators, there is nothing to control and bring balance to the adelgid populations.

Within in a few years, the Wykoff Run adelgid population will spread into adjacent areas. To the east in nearby Lower Jerry Run lies a stand of towering, large-diameter virgin hemlocks. These ancient trees' days are numbered.

Little by little, the alien insect pest will overrun the remaining pockets of healthy hemlock trees. Our mountain brook trout streams that were once shaded by heavy hemlock canopy will warm as their canopy is removed. Our wildlife will gradually lose the dense winter cover.

Dead snags will stand as forlorn monuments of what the hemlock used to be. We will tell our children and grandchildren about the great hemlock and how important it used to be to our forests. They will never be able to fully grasp the importance of the hemlock, much as we can never fully understand the importance of the American chestnut that dominated the forests known to our fathers and grandfathers.

The only thing we have in our favor is that severe cold does seem to retard adelgid population growth. So we'll have to pray for some oldfashioned winters, with plenty of nights well below zero, and remain vigilant as this exotic forest pest advances into our region.